Transfer materials

ABSTRACT

Transfer materials which comprise a substrate which has been printed or otherwise coloured with one or more inks each of which contains two or more sublimable disperse dyestuffs which give a similar shade but which are of differing degrees of volatility, and the use of the said transfer materials for colouring synthetic textile materials.

United States Patent 1191 Clarke et al.

1 June 10, 1975 TRANSFER MATERIALS [75] Inventors: William Clarke; Timothy Leslie Dawson; Douglas Alan Nichols, all of Manchester, England [73] Assignee: Imperial Chemical Industries Limited, London, England 22 Filed: Nov. 28,1973

[21] App]. No.: 419,880

[30] Foreign Application Priority Data [56] References Cited UNITED STATES PATENTS 1,993,524 3/1935 Poschel 8/2.5

9/1969 Collez ..8/l4

Primary Examiner-Ralph S. Kendall Assistant Examiner-Bruce H. Hess Attorney, Agent, or FirmCushman, Darby & Cushman [5 7] ABSTRACT Transfer materials which comprise a substrate which has been printed or otherwise coloured with one or more inks each of which contains two or more sublimable disperse dyestuffs which give a similar shade but which are of differing degrees of volatility, and the use 'of the said transfer materials for colouring synthetic textile materials.

6 Claims, No Drawings TRANSFER MATERIALS This invention relates to transfer materials for use in the process of transfer colour printing.

In the known process of transfer colour printing a transfer material comprising a substrate such as paper which carries a printed pattern which has been produced from inks containing sublimable dyestuffs is placed in contact with a synthetic textile material which are then heated together in contact, Under these conditions the dyestuff is transferred by volatilisation or sublimation from the transfer material to the textile material which is thus coloured in a pattern which is a mirror image of that appearing on the transfer material. Whilst this process is suitable for use with thin textile materials, the use of thick textile materials, for example carpets or rugs, can give rise to serious difficulties in that only the surface is coloured (i.e. the tips of the tufts or pile), the majority of the goods remaining uncoloured so that they exhibit the well known defect of grinning. In the case of tufted or needlefelt carpets this defect can be overcome by carrying out the process of transfer colour printing at reduced pressures, preferably at a pressure of less than lOO mms of mercury, as described and claimed in our British Specification No. 1,271,327, as by the use of the reduced pressures very much better penetration of thick textile materials is obtained. However, it has been found that when the process of transfer colour printing at reduced pressures is applied to very thick goods, such as simulated fur fabrics or rugs having a very long pile of a synthetic textile material, and especially those having a loose or open pile, whilst the degree of penetration down the pile is very good so that little or none of the pile is uncoloured, the tips of the pile are much paler in shade than the remainder of the pile. The surface of such goods thus appears to be only lightly coloured and exhibits the defect known as frostiness.

It has now been found that this defect can be over come if a transfer material is used which has been printed with one or more inks each of which contains two or more sublimable dyestuffs which give a similar shade but which differ in volatility. Using such transfer materials in the process of transfer colour printing or rugs having a very long pile the more volatile dyestuff or dyestuffs penetrates to the base of the pile whilst the less volatile dyestuff or dyestuffs only colours the top of the pile. The pile is therefore coloured in a substantial uniform shade from the base to the tips of the pile thus obviating the defects of grinning and frostiness.

Thus according to the present invention there are provided transfer materials which comprise a substrate which has been printed or otherwise coloured with one or more inks each of which contains two or more sublimable disperse dyestuffs which give a similar shade but which are of differing degrees of volatility.

The transfer materials of the invention can be produced in conventional manner by printing a substrate with one or more inks each of which contains two or more sublimable disperse dyestuffs which give a similar shade but are of differing degrees of volatility, by conventional printing processes, for example by gravure, lithographic, flexographic or screen printing processes on printing machinery which is commonly employed for this purpose, drying being carried out after the application of each ink.

The inks used to print the said transfer materials are of the types which are conventionally employed for this purpose, the only difference residing in the use of the two dyestuffs having properties as previously stated. However, in order to obtain the required shades it is frequently necessary to employ mixtures of dyestuffs, for example a mixture ofa yellow and ofa blue dyestuff in order to produce greens, and transfer materials which have been printed with inks containing such mixtures of dyestuffs are also within the scope of the pres ent invention. Where mixture of dyestuffs are in fact used then it is necessary to use mixtures of at least two dyestuffs of each colour present in the ink, one dyestuff of each colour differing in the degree of volatility from the other dyestuff or dyestuffs of the same colour. Thus, for example, in order to produce a green ink it would be necessary to use at least two yellow dyestuffs which give a similar shade but differing degrees of volatility and at least two blue dyestuffs which give a similar shade but of differing degrees of volatility. When selecting such dyestuffs for mixtures of this type it is preferable, in order to avoid diffusion effects appearing in the printed textile materials, thus causing colour variations due to separation of the individual dyestuff components, to use pairs or dyestuffs which have similar differences in volatility. Thus, for example, in the case of a green mixture, the less volatile yellow dyestuff should volatilise at substantially the same rate as the less volatile blue dyestuff, and similarly for the more volatile yellow and blue dyestuffs. However, in some cases it may not be possible to obtain two single dyestuffs giving the same shade in which case it is possible to use a single dyestuff of the appropriate shade and to match it with a mixture of dyestuffs which differs in volatility to that of the single dyestuff. Thus, for example, in order to produce a violet shade, the less volatile dyestuff could be a homogeneous violet dyestuff whilst the more volatile dyestuff could be a mixture of a red and a blue dyestuff (which mixture is of the same shade as the violet dyestuff) which, whilst they are more or less volatile than the violet dyestuff volatilise at substantially the same rate.

Since the actual shades obtained from a particular disperse dyestuff, or a mixture of disperse dyestuffs in the case of tertiary shades, can vary depending on the substrate to which they are being applied, it is advisable in selecting dyestuffs to be used to prepare the transfer papers of the invention to match the shades by transfer printing the separate dyestuffs (or, when appropriate, mixtures of the separate dyestuffs) on to a thin textile material of the same type of fibres which are to be printed with the final transfer material. Further in order to select dyestuffs having the appropriate differences in volatility it is usually necessary to carry out tests on the separate dyestuffs (or, when appropriate, on mixtures of the separate dyestuffs) using the textile materials and the transfer conditions which are to be employed in commercial production.

Preferably the dyestuffs giving a similar shade or shades, but of differing degrees of volatility, used to obtain the transfer papers of the invention differ from each other by a r factor of at least 10 seconds where I is the time required to achieve 50% penetration of a carpet pile when carried out under the following conditions, the degree of penetration being principally related to the volatility of the dyestuff.

A printing ink of the following composition Parts Pure. diluent free. dyestuff l lsopropanol l 10 Toluene 880 Ethyl cellulose N22 50 1.000

is prepared by ball milling the components, and the ink is then applied to a flexographic printing paper (55 gms./sq. metre) using a No.4 K-Bar applicator (R. K. Chemical Co. Ltd.) to give a wet coating 36 p. thick, and the printed paper is then dried at room temperature. Portions of the resulting printed paper are then placed in contact with pieces of a carpet (the printed surface of the paper being in contact with the pile of the carpet) having the following description:- a 1/10 gauge, 4 mm. loop-pile 400 gms./sq.m., 3.5 stitches- /inch, carpet tufted from nylon 6:6 yarn (ICI K201, 2720 dtex, 136 filament) into a jute backing. The resulting composite samples are then placed in a vacuum transfer press, such as that described in US. applica- I tion Ser. No. 174906 and transfer effected at 220C and an applied vacuum of 710 mms. of mercury (i.e. 50 mms. pressure) for different periods of time varying from to 120 seconds. The degree of penetration of the dyestuff into the carpet pile is then measured, and from the time/penetration figures the time of heating in order to achieve 50% pile pentration (r can be calculated (i.e. the time of heating required for the dyestuff to diffuse from the paper in contact with the carpet surface to a depth of 2 mms. in the pile).

Thus, for example, one dyestuff can have a r factor of 15 seconds and the second dyestuff, which gives a similar shade to the first, will then have a r factor of at least 25 seconds. If a third dyestuff giving a similar shade is also present then this will have a factor which is at least 10 seconds greater than that ofthe second dyestuff. Preferably the difference in the t factors of the dyestuffs of similar shade is at least seconds.

In. actual practice the degree of penetration of each individual dyestuff is also dependent to a certain extent on other conditions such as concentration of the dyestuff in the ink and/or on the paper, the actual conditions under which transfer is carried out, and on the textile material to which transfer is taking place. However for the purpose of selecting suitable combinations of dyestuffs based on the t values it is necessary that these other factors be disregarded and the factor be determined under the exact conditions specified above.

The disperse dyestuffs used to obtain the transfer materials of the invention can be of any of the recognised classes of disperse dyestuffs, in particular of the azo, anthraquinone, nitro and quinphthalone series such as are commercially available or are described in, for example, the third edition of the Colour Index which was published in 1971. Such dyestuffs are normally the commercially available forms containing considerable amounts of dispersing agents and/or other diluents, but the corresponding pure dyestuffs (i.e. free from dispersing agents and/or diluents) can also be used, particularly in the case of inks based on organic liquids as the liquid media.

The substrate for the transfer materials of the invention is preferably paper, but, if desired, other substrates such as aluminium foil can be used. The substrate can be porous or non-porous.

The inks required for the production of the transfer material of the invention can be obtained in conventional manner, for example by milling together a mixture of the dyestuffs, a binder or resin, a liquid medium, and optionally additional components such as dispersing agents.

Water can be used as the liquid medium, but it is preferred to use an organic liquid or mixtures thereofffor example hydrocarbons such as toluene, xylene and aliphatic petroleum fractions which boil in the region of 80 to 200C, alcohols such as isopropanol, ketones such as methylethyl ketone, and esters such as methyl acetate.

The binder or resin used in the inks can be any of the conventional binders or resins which are used in printing inks. the choice of binder or resin which is to be used depending on the liquid medium and the physical properties of the resulting inks. Such binders or resins are described in for example the first edition of the Printing Ink Manual which was published in 1961 and in Ink Technology for Printers and Students by E. A. Apps which was published in 1963. In the case of inks based on organic liquids as the media particularly suitable binders are cellulose ethers which are soluble in such liquids, such as ethyl cellulose and hydroxypropylcellulose.

The transfer materials of the invention are particularly valuable for the colouration of thick synthetic textile materials, expecially carpets or rugs having a long pile or simulated fur fabrics, the transfer being effected in, for example, intermittent transfer presses which operate under an applied vacuum, such as are described in our copending US. applications Ser. Nos. 174,906 and 334,688. When effecting the transfer the printed surface of the transfer material is in contact with the surface of the synthetic textile material which is to be coloured.

As examples of synthetic textile materials there may be mentioned cellulose acetate, such as secondary cellulose acetate and cellulose triacetate, textile materials, polyacrylonitrile textile materials, polyurethane textile materials, aromatic polyester, such as polyethyleneterephthalate, textile materials and synthetic polyamide textile materials such as those known as Nylon 6, Nylon 6:6 and Quiana (a registered trade mark). If desired mixtures of such materials can be used.

The transfer materials of the invention when used for the transfer colour printing of thick synthetic textile materials, in particular carpets or rugs having a long pile or simulated fur fabrics, give well penetrated colourations and there is little variation in shade throughout the depth of the colourations.

The invention is illustrated but not limited by the following Examples in which the parts and percentages 0 are by weight.

Three printing inks were prepared by gravel milling together for 24 hours the listed components:-

Parts 25 l-amino-4-hydroxyanthraquinone (t 15 secs.) 25 l:4-diamino-2-methoxyanthraquinone (t secs.) 5O ethylcellulose N22 (Hercules Powder Co.) 300 isopropanol 800 toluene C ontinued lnk B Parts 25 l:4-di(methylamino)anthraquinonc (t secs.) 25 Partially methylated 1:8-hydroxy- (t 45 Secs.)

4:5-diaminoanthruquinone 50 ethylccllulose N22 l 00 isopropanol 800 toluene 1,000 lnk C Parts 25 2'hydroxy-5-methyl-4'-acetylaminoazobenzenc (t 60 sees) 25 N-ethylindole-3c2'-isoindoleindigo (t 30 secs.) 5O ethylcellulose N22 I00 isopropanol EXAMPLE 4 800 toluene 1.000 A printing ink comprising a mixture of EXAMPLE I i .is applied to paper by gravure printing using a plain rol- A mixture of 80 parts of Ink A and parts of lnk B the prmted Paper are applied to paper by gravure priming using a plain 25 A piece of the resulting transfer paper is placed in toner and the paper is then dried contact with a nylon rug (the printed surface of the A piece of the transfer paper so obtained is placed in Paper being In Contact f the P of the rug) and Contact i h a piece f a nylon tug (comprising a i transfer then effected using the press and conditions of Nylon 6:6 fibres tufted into a hessian backing), the Specified in Example The nylon g is I r d a blurimed surf of the paper b i i t t with h ish-violet shade with good penetration of the pile and pile of the rug, and transfer printing is then effected in little or no variation in the depth of shade down the an intermittent vacuum press of the type described in pile. our co-pending US. application Ser. No. 174906 for 45 seconds at 240C using an applied vacuum of 710 mms 'of mercury. The nylon rug is overall coloured in a violet EXAMPLE 5 shade with excellent penetration of the pile and there is little or no variation in the depth of shade of the pile. A printing ink comprising a mixture of 10 parts of 4-nitro-4'-aminoazobenzene (t 15 secs.) 15 parts of 4-nitro-4-anilinoazobenzene (t secs.)

5 parts of l-phenylazo-4-(p-hydroxyphenylazo)naphthalene (t 65 secs.) parts of ethylcellulose N22 120 parts of mesitylene 800 parts of xylene Wparts EXAMPLE 2 is applied to paper by gravure printing, and the printed paper is then dried. Ink 3 is pp to P p y gravure Priming using a A piece of the resulting transfer paper is placed in plain roller and th pap r is then driedcontact with a polyester needlefelt having a velour type The resulting P p is used to transfer Print a 50 surface and transfer then effected using the press and nylon rug using the press and conditions described in conditions specified in Example 1 except that the Example I. The nylon rug is overall coloured in a blue perature used was 210C (instead of 2400C). The need shade with excellent penetration of the pile and there lefelt is printed in an Orange Shade is little or no variation in the depth of shade of the pile. A Similar result is Obtained when this transfer paper is used to colour an acrylic fibre cut pile carpet, the EXAMPLE 3 transfer being effected at a temperature of 175C.

Paper is similarly printed with Ink A or Ink C or a mixture of equal parts of Inks A and C or a mixture of EXAMPLE 6 equal parts of Inks B and The resulting papers are The printing ink described in Example 5 is printed on then used to transfer print a nylon rug using the press to paper on a rotary screen printing machine carrying and conditions described in Example I. The nylon rugs a design, and the primed papa is then dried in a hot air are respectively coloured in red, yellow, orange and Stream at a temperature below 150C green shades with excellent penetration of the pile and A piece f the resulting t f paper is placed in little or no variation in the depth of shade of the pile. Contact i h a nylon shag pile Cal-pet tile and transfer then effected using the press and conditions specified in Example 1. The carpet tile is printed in a bright orange and white design, and there is excellent penetration of those parts of the pile in those parts of the tile which have been coloured orange.

EXAMPLE 7 A mixture of 20 parts l-amino-4-hydroxyanthraquinone 20 parts l:4-diamino-Z-methoxyanthraquinone 5 parts l:4-di(methylamino)anthraquinone 5 parts Partially methylated lz8-dihydroxy-4z5- diaminoanthraquinone 25 parts 507: solution in an'aliphatic petroleum spirit of a tolylene diisocyanate/lz6-hexanediol/hydroxyester of l2-hydroxystearic acid and a hexadecanol/octadecanol mixture, condensate obtained as described in Example 1 of Belgian Patent Specification No. 795,748 125 parts Aliphatic petroleum fraction boiling at 100 to 120C is ball milled to give a fluid dispersion in which the dyestuff particles are smaller than 3 p. and the majority are less than 1 1..

The resulting dispersion is then added to a solution of 50 parts of ethylcellulose N22 in a mixture of 100 parts of isopropanol and 850 parts of toluene.

The resulting ink is applied to paper by gravure printing using a plain roller and the paper is then dried.

The resulting paper is used to transfer print a nylon rug using the press and conditions specified in Example l. The rug is coloured a violet shade and there is excellent penetration of the pile with little or no variation in the shade of the pile.

We claim:

1. A transfer material which comprises a substrate which has been printed with at least one ink which contains two or more sublimable disperse dyestuffs which give a similar shade but having differing degrees of volatility.

2. A transfer material as claimed in claim 1 wherein each dyestuff giving a similar shade consists of a mixture of dyestuffs each of which volatilises at substantially the same rate.

3. A transfer material as claimed in claim 1 wherein at least one of the dyestuffs consists of a single dyestuff which gives the appropriate shade and the remaining dyestuff or dyestuffs each consist of a mixture of dye stuffs which together give the same shade as one of the single dyestuffs, the dyestuffs present in each mixture having substantially the same volatility which is either greater or smaller than that of the single dyestuff of the same shade.

4. A transfer material as claimed in claim 1 wherein the dyestuffs which give a similar shade differ from each other by a r factor of at least 10 seconds.

5. A transfer material as claimed in claim 4 wherein the dyestuffs which give a similar shade differ from each other by a I factor of at least 15 seconds.

6. A transfer material as claimed in claim 1 wherein the substrate is paper.

* =l l l 

1. A TRANSFER MATERIAL WHICH COMPRISES A SUBSTRATE WHICH HAS BEEN PRINTED WITH AT LEAST ONE INK WHICH CONTAINS TWO OR MORE SUBLIMABLE DISPERSE DYESTUFFS WHICH GIVE A SIMILAR SHADE BUT HAVING DIFFERING DEGREES OF VOLATILITY.
 2. A transfer material as claimed in claim 1 wherein each dyestuff giving a similar shade consists of a mixture of dyestuffs each of which volatilises at substantially the same rate.
 3. A transfer material as claimed in claim 1 wherein at least one of the dyestuffs consists of a single dyestuff which gives the appropriate shade and the remaining dyestuff or dyestuffs each consist of a mixture of dyestuffs which together give the same shade as one of the single dyestuffs, the dyestuffs present in each mixture having substantially the same volatility which is either greater or smaller than that of the single dyestuff of the same shade.
 4. A transfer material as claimed in claim 1 wherein the dyestuffs which give a similar shade differ from each other by a t50 factor of at least 10 seconds.
 5. A transfer material as claimed in claim 4 wherein the dyestuffs which give a similar shade differ from each other by a t50 factor of at least 15 seconds.
 6. A transfer material as claimed in claim 1 wherein the substrate is paper. 